In the space of two weeks, Hurricane Gustav has caused an estimated $3 billion in losses in the U.S. and killed about 110 people in the U.S. and the Caribbean, catastrophic floods in northern India have left a million people homeless.

　　If it seems like disasters are getting more common, it's because they are. But some disasters seem to be affecting us in worse ways — and not for the reasons you may think. Floods and storms have led to most of the excess damage. The number of flood and storm disasters has gone up 7.4% every year in recent decades, according to the Centre for Research on the Epidemiology of Disasters. (Between 2000 and 2007, the growth was even faster, with an average annual rate of increase of 8.4%.) Of the total 197 million people affected by disasters in 2007, 164 million were affected by floods.